1. Field of the Invention
The present invention relates generally to projectile detection, and, more particularly, but not by way of limitation, to devices, systems, and methods for detecting characteristics of a projectile and/or the projectile source, such as may be used to derive the position of the projectile source.
2. Description of Related Art
Snipers can present a significant hazard to deployed soldiers and to the public at large. Single-shot gunfire events can be difficult to locate; thus, snipers may escape detection and create a repetitive danger. More overt attackers may also fire shots from a location to initiate a fire fight. In some environments, the source of such gunfire (or other projectiles) may be difficult to locate. For example, in urban environments, echoes may make it difficult for a person to audibly locate the source of gunfire, and/or obstructions may make it difficult for a person to visually locate the source of a projectile. By way of another example, when a sniper fires from a relatively large distance, the noise of the gunfire that is perceived by a person may be significantly reduced, thereby making it difficult for a person to even realize that the gunfire is directed in his or her direction. A number of systems have been developed that use one or more microphones or other sensors distributed over relatively large distances to detect gunfire and derive the approximate direction and/or range of the source of the gunfire, as well as other characteristics of the projectiles.
Some soldier-wearable systems have also been developed. For example, U.S. patent application Ser. No. 10/905,788, filed Jan. 20, 2005 and published as Pub. No. US 2005/0237186, now U.S. Pat. No. 7,750,814, and hereby incorporated by reference in its entirety, discloses a soldier-wearable system for acoustic event detection that uses a single sensor. Other soldier-wearable systems have been proposed, such as, for example, the EARS system manufactured by Planning Systems Inc., QinetiQ North America, 12030 Sunrise Valley Drive Suite 400, Reston, Va. 20191, U.S.A.; and the Boomerang Warrior system manufactured by BBN Technologies, 10 Moulton Street, Cambridge, Mass. 02138, U.S.A.
The following references may disclose examples of projectile-detection systems, and may facilitate a more complete understanding of the various embodiments of the present invention and uses for the various embodiments of the present invention: (1) U.S. patent application Ser. No. 10/905,788, filed Jan. 20, 2005, published as Pub. No. US 2005/0237186, and issued as U.S. Pat. No. 7,750,814; (2) U.S. patent application Ser. No. 11/042,414, filed Jan. 24, 2005 and published as Pub. No. US 2006/0114749, now U.S. Pat. No. 7,266,045; (3) U.S. patent application Ser. No. 11/227,446, filed Sep. 15, 2005 and published as Pub. No. US 2007/0230269, now U.S. Pat. No. 7,433,266; (4) U.S. patent application Ser. No. 11/482,899, filed Jul. 7, 2006 and published as Pub. No. US 2008/0008044, now abandoned; (5) U.S. patent application Ser. No. 12/074,884, filed Mar. 7, 2008 and published as Pub. No. US 2008/0162089, now U.S. Pat. No. 8,005,631; (6) U.S. patent application Ser. No. 10/593,922, filed Sep. 24, 2007 and published as Pub. No. US 2008/0167835 now U.S. Pat. No. 7,765,083; (7) U.S. patent application Ser. No. 11/930,072, filed Oct. 30, 2007 and published as Pub. No. US 2008/0221793; (8) U.S. Pat. No. 5,241,518, filed Feb. 18, 1992; (9) U.S. Pat. No. 5,544,129, filed Aug. 30, 1994; (10) U.S. Pat. No. 5,912,862, filed Sep. 23, 1996; (11) U.S. Pat. No. 6,178,141, filed May 28, 1999; (12) U.S. Pat. No. 6,185,153, filed Mar. 16, 2000; (13) U.S. Pat. No. 6,847,587, filed Jan. 24, 2003; (14) U.S. Pat. No. 7,126,877, filed Aug. 24, 2004; (15) U.S. Pat. No. 7,139,222, filed Jan. 20, 2005; (16) U.S. Pat. No. 7,190,633, filed Aug. 24, 2004; (17) U.S. Pat. No. 7,203,132, filed Apr. 7, 2006; (18) U.S. Pat. No. 7,266,045, filed Jan. 24, 2005; (19) U.S. Pat. No. 7,292,501, filed Aug. 24, 2004; (20) U.S. Pat. No. 7,362,654, filed May 24, 2005; (21) U.S. Pat. No. 7,372,772, filed Feb. 23, 2007; (22) U.S. Pat. No. 7,408,840, filed Oct. 13, 2006; (23) U.S. Pat. No. 7,420,878, filed Jan. 20, 2005; (24) U.S. Pat. No. 7,409,899, filed Nov. 26, 2004; and (25) U.S. Pat. No. 7,433,266, filed Sep. 15, 2005. The foregoing references numbered (1) through (25) are hereby incorporated by reference in their entireties.